A scroll compressor is provided. The scroll compressor may include a casing, a discharge cover to partition an inside of the casing into suction and discharge spaces, a first scroll, a second scroll that defines compression chambers together with the first scroll and includes an intermediate pressure discharge hole that communicates with a compression chamber having an intermediate pressure of the compression chambers, a back pressure plate that defines a back pressure chamber that accommodates a refrigerant discharged from the intermediate pressure discharge hole, a floating plate that defines the back pressure chamber together with the back pressure plate, and a gasket disposed between the back pressure plate and the second scroll and having an intermediate pressure communication hole that allows the intermediate pressure discharge hole to communicate with the intermediate pressure suction hole. The gasket may block communication between the back pressure chamber and the suction and discharge spaces.

A co-rotating scroll is disclosed having a motor having a shaft, a drive scroll connected to the shaft for moving the drive scroll, a driven scroll connected to the drive scroll to be moved by the drive scroll, and an idler shaft for aligning the drive scroll and the driven scroll and for allowing the driven scroll to be moved by the drive scroll.

Scroll expander including a bypass passage and a bypass valve configured to open and close the bypass passage without significantly increasing the length in the shaft direction of the scroll expander. Scroll expander 23 includes suction port 513 which allows a high-pressure flow of a working fluid to enter and guides the entering flow of the working fluid into an expansion chamber. Discharge port 523 allows the working fluid expanded to a lower pressure in the expansion chamber to flow out. Bypass passage 27 communicates suction port 513 with the discharge port 523 while bypassing the expansion chamber. Bypass valve 28 is configured to open and close bypass passage 27. Suction port 513, bypass passage 27 and a bypass valve attaching portion 514 for attaching the bypass valve 28 are formed in a base plate of the fixed scroll 51.

A scroll compressor is provided that may include a casing including a rotational shaft, a discharge cover fixed inside of the casing to partition the inside of the casing into a suction space and a discharge space, a first scroll that is revolved by rotation of the rotational shaft, a second scroll that defines a plurality of compression chambers together with the first scroll, the second scroll having an intermediate pressure discharge hole that communicates with a compression chamber having an intermediate pressure of the plurality of compression chambers, a back pressure plate that defines a back pressure chamber that accommodates a refrigerant discharged from the intermediate pressure discharge hole, a floating plate movably disposed on or at a side of the back pressure plate to define the back pressure chamber together with the back pressure plate, and an elastic member disposed between the floating plate and the discharge cover to provide an elastic force to the floating plate.

A scroll compressor is provided. The scroll compressor may include a fixed scroll including a fixed wrap, and an orbiting scroll including an orbiting wrap coupled to the fixed wrap to form a pair of compression chambers. An entire cross-sectional area of bypass holes formed at a compression chamber with a larger volume reduction gradient between the compression chambers may be formed to be larger than an entire cross-sectional area of bypass holes formed at the other compression chamber to prevent over-compression at the compression chamber with the larger volume reduction gradient, thereby enhancing an entire efficiency of the compressor.

Scroll expander including a bypass passage and a bypass valve configured to open and close the bypass passage without significantly increasing the length in the shaft direction of the scroll expander. Scroll expander 23 includes suction port 513 which allows a high-pressure flow of a working fluid to enter and guides the entering flow of the working fluid into an expansion chamber. Discharge port 523 allows the working fluid expanded to a lower pressure in the expansion chamber to flow out. Bypass passage 27 communicates suction port 513 with the discharge port 523 while bypassing the expansion chamber. Bypass valve 28 is configured to open and close bypass passage 27. Suction port 513, bypass passage 27 and a bypass valve attaching portion 514 for attaching the bypass valve 28 are formed in a base plate of the fixed scroll 51.

A co-rotating scroll is disclosed having a motor having a shaft, a drive scroll connected to the shaft for moving the drive scroll, a driven scroll connected to the drive scroll to be moved by the drive scroll, and an idler shaft for aligning the drive scroll and the driven scroll and for allowing the driven scroll to be moved by the drive scroll.